Answer:
Mass = 14.64 g
Explanation:
Given data:
Volume of solution = 1.25 L
Molarity of Solution = 0.15 M
Mass of CaF₂ = ?
Solution:
Molarity is used to describe the concentration of solution. It tells how many moles are dissolve in per litter of solution.
Formula:
Molarity = number of moles of solute / L of solution
We will calculate the number of moles of CaF₂ and then determine the mass by using number of moles.
0.15 M = number of moles of solute / 1.25 L
number of moles of solute = 0.15 M × 1.25 L
number of moles of solute = 0.1875 mol/L × L
number of moles of solute = 0.1875 mol
Mass in gram:
Mass = number of moles × molar mass
Mass = 0.1875 mol ×78.07 g/mol
Mass = 14.64 g
Answer:
A scientific question to be asked is; <em>What is the average speed of the toy car?</em>
Explanation:
A scientific question is a question which is well defined, the values in the question can be measured, and the inputs and outputs related to the question are controllable
The parameters measured in the experiment are;
The time elapsed during the movement of the car, <em>Δt</em>
The distance the car moves, <em>d</em>
From the obtained measurements, the value can be calculated is the average speed of the toy car as follows;
Therefore, a scientific question to be asked that will be answered by doing the experiment is; What is the average speed of the toy car?
Explanation:
Solubility is determined by the principle , "like dissolves like" .
i.e. , if a compound is polar then it will dissolve in a polar compound only , and
if a compound is non - polar then it will dissolve in a non - polar compound only .
Hence , from the question ,
Water is a polar molecule , and hence it will dissolve only the polar molecule , i.e. , from the given options the polar molecule is , iii. K₂SO₄
Hexane , is a non - polar molecules , hence it will dissolve only the non polar molecule , i.e. , from the given options the non polar molecule is i. Butane .
Answer: Aluminum, 
Explanation:
Density is defined as the mass contained per unit volume. It is characteristic of a substance.
Given : Mass of object = 8.44 grams
Volume of object=
Putting in the values we get:
Thus density of the object will be which matches that of aluminium.
Answer:
46.71g
Explanation:
First, we'll begin by calculating the number of mole of KNO3 present in the solution. This is illustrated below below:
Data obtained from the question:
Molarity = 2.50 M
Volume = 185 mL = 185/1000 = 0.185L
Mole =?
Molarity = mole /Volume
Mole = Molarity x Volume
Mole = 2.5 x 0.185
Mole = 0.4625 mole
Now we can obtain the mass of KNO3 as follow:
Molar Mass of KNO3 = 39 + 14 + (16x3) = 39 + 14 + 48 = 101g/mol
Number of mole of KNO3 = 0.4625 mole
Mass of KNO3 =?
Mass = number of mole x molar Mass
Mass of KNO3 = 0.4625 x 101
Mass of KNO3 = 46.71g
